18
Other Biomedical
Imaging Techniques
18.1 INTRODUCTION AND OVERVIEW
From our discussion in previous chapters, it will have become evident that the discipline of biomedical imaging has two main fields of application: anatomical imaging
and functional imaging. Even though the distinction between anatomical and functional imaging is sometimes somewhat arbitrary, these two categories discriminate
the overall capabilities of the imaging modalities.
Another group of biomedical imaging system, which is not particularly relevant
in diagnostics and treatment planning, has become widely used. This group of imaging, commonly referred to as biometrics, falls in the category of methods for personal identification.
Several imaging techniques that can provide near-real-time and three-dimensional
(3-D) imaging of biological samples have been described in the previous chapters.
Examples are magnetic resonance imaging, x-ray computed tomography, and ultrasound. Each methodology has certain applicability for specific imaging problems.
However, while diagnosis of many diseases in their early stages requires a cellular level
of resolution, none of these techniques is capable of achieving a reasonable resolution on
the cellular level. Cellular imaging requires spatial resolution of less than 10 microns.
In this chapter, we first briefly describe anatomical imaging methods, not covered in previous chapters. The majority of these methods have cellular resolution.
Under anatomical imaging category, the imaging techniques on regular optical
microscopy, fluorescent microscopy, confocal microscopy, near-field scanning optical microscopy (NSOM), electrical impedance imaging, and electron microscopy
are described briefly. Out of these methods, the first four imaging modalities can
provide cellular resolution and are mainly used in vitro. Electrical impedance imaging, although not providing cellular resolution, is applied in vivo. Imaging methods
such as optical microscopy depend on having access to a sample of the biological
tissue under study. A biopsy is often performed to provide the sample.
The functional imaging method covered in this chapter is medical infrared imaging. Under biometrics, the use of fingerprint, retina, and iris recognition for identification purposes is outlined.
18.2 OPTICAL MICROSCOPY
The common microscope is probably the most well-known biomedical imaging
device. Apart from some technical limitations, microscopes show the detail on small
biological structures up to the smallest building block of life, the cell.
355
Other Biomedical
Imaging Techniques
18.1 INTRODUCTION AND OVERVIEW
From our discussion in previous chapters, it will have become evident that the discipline of biomedical imaging has two main fields of application: anatomical imaging
and functional imaging. Even though the distinction between anatomical and functional imaging is sometimes somewhat arbitrary, these two categories discriminate
the overall capabilities of the imaging modalities.
Another group of biomedical imaging system, which is not particularly relevant
in diagnostics and treatment planning, has become widely used. This group of imaging, commonly referred to as biometrics, falls in the category of methods for personal identification.
Several imaging techniques that can provide near-real-time and three-dimensional
(3-D) imaging of biological samples have been described in the previous chapters.
Examples are magnetic resonance imaging, x-ray computed tomography, and ultrasound. Each methodology has certain applicability for specific imaging problems.
However, while diagnosis of many diseases in their early stages requires a cellular level
of resolution, none of these techniques is capable of achieving a reasonable resolution on
the cellular level. Cellular imaging requires spatial resolution of less than 10 microns.
In this chapter, we first briefly describe anatomical imaging methods, not covered in previous chapters. The majority of these methods have cellular resolution.
Under anatomical imaging category, the imaging techniques on regular optical
microscopy, fluorescent microscopy, confocal microscopy, near-field scanning optical microscopy (NSOM), electrical impedance imaging, and electron microscopy
are described briefly. Out of these methods, the first four imaging modalities can
provide cellular resolution and are mainly used in vitro. Electrical impedance imaging, although not providing cellular resolution, is applied in vivo. Imaging methods
such as optical microscopy depend on having access to a sample of the biological
tissue under study. A biopsy is often performed to provide the sample.
The functional imaging method covered in this chapter is medical infrared imaging. Under biometrics, the use of fingerprint, retina, and iris recognition for identification purposes is outlined.
18.2 OPTICAL MICROSCOPY
The common microscope is probably the most well-known biomedical imaging
device. Apart from some technical limitations, microscopes show the detail on small
biological structures up to the smallest building block of life, the cell.
355